Composition for imparting non-permanent soil-release characteristics comprising an aqueous solution of polycarboxylate copolymer and water-soluble amine

ABSTRACT

A composition for applying non-permanent soil-release finish to fabrics from dilute solution comprising a polycarboxylate polymer having an acid equivalent weight of from about 110 to 175, and a water-soluble amine. A preferred polycarboxylate polymer is a copolymer of 2/3 methacrylic acid/ 1/3 ethylacrylate. The composition is particularly useful for applying a soil-release finish in the rinse cycle of a home laundry process.

United States Patent [191 Dickson COMPOSITION FOR IMPARTINGNON-PERMANENT SOIL-RELEASE CHARACTERISTICS COMPRISING AN AQUEOUSSOLUTION OF POLYCARBOXYLATE COPOLYMER AND WATER-SOLUBLE AMINE Robert E.Dickson, Belle Mead, NJ.

Colgate-Palmolive Company, New York, NY.

Filed: Mar. 24, 1972 Appl. No.: 237,916

Inventor:

Assignee:

US. Cl 260/29.6 N, 8/1 15.6, 252/8.6,

117/1895 A, 252/DIG. 2 Int. Cl..... D06m 15/26, CO8f 3/42, CO8f 15/36Field of Search 260/29.6 N; 117/1385 References Cited UNITED STATESPATENTS 9/1956 Dreisbach 260/29.6

[45] June 28, 1974 Primary ExaminerWilliam H. Short AssistantExaminerPeter F. Kulkosky Attorney, Agent, or Firm-Herbert S. Sylvester;Murray M. Grill; Norman Blumenkopf ABSTRACT 8 Claims, N0 DrawingsCOMPOSITION FOR IMPARTING NON-PERMANENT SOIL-RELEASE CHARACTERISTICSCOMPRISING AN AQUEOUS SOLUTION OF POLYCARBOXYLATE COPOLYMER ANDWATER-SOLUBLE AMINE BACKGROUND OF THE INVENTION This invention relatesto a process for treating a textile substrate to impart a soil-releasecharacteristic thereto which can conveniently be used in the rinse cycleof a home laundry procedure.

The genesis of synthetically produced textile fibers has brought about atremendous effort in the textile industry along numerous avenues. Therehas been much research effort directed to the improvement of thesesynthetic fibers per se, and improved blends of synthetically producedfibers with natural fibers, i.e., cellulosic fibers or keratinousfibers. Results of this research have been successful and the directionof research has been diverted from the synthetic polymer per se and/orblends of said polymers with other naturally occurring fibers. Recently,fiber research has been directed towards improving physicalcharacteristics of fabric produced from synthetic fibers and/or blendsof these synthetic fibers with naturally occurring fibers, specifically,to the physical characteristics and/or endurance properties of garmentsproduced from synthetic fabrics and/or fabric produced from blends ofsynthetic fibers and naturally occurring fibers. I

Much research has been directed to the attainment of a garment havingimproved soil-release properties. Many of the synthetically producedfibers that are presently being incorporated in blends with naturallyoc-' curring fibers have a propensity to accept and retain oily grimeand dirt. Accordingly, when the garment is being worn the soil and/oroily materials accumulate on the garment and settle in the fabric. Oncethe garment becomes soiled, it is then subjected to a cleaning processfor removal of the dirt and/or oily deposits, and only a dry cleaningprocess will successfully clean the garment.

The cleaning process normally employed, however, is washing in aconventional home washing machine by the housewife. During a wash cycle,it is virtually impossible to remove the soil and/or oily stains fromthe garment, and secondly, assuming that the undesirable materials areremoved from the garment or a fairly clean garment is being washed, soilremaining in the wash water is redeposited onto the garment prior to theend of the wash cycle. Hence, when the garment is removed from thewashing machine and subsequently dried, it has not been properlycleaned. Such a condition, heretofore unavoidable, is quitedisadvantageous in that the garment after being worn never again assumesa truly clean appearance, but instead tends to gray and/or yellow due tothe soil and/or oily materials deposited and remaining thereon. Furtheruse and washing of the garment increases the intensity of the graying tothe point that ultimately the garment is unacceptable for further weardue to its discoloration. The process of the present invention solvesthe soiling problem as hereinafter described.

The problem heretofore confronted with fabrics having synthetic fibersincorporated therein, or made entirely of synthetic fibers, has beenthat the synthetic fibers as well as being hydrophobic, are oleophilic.

Therefore, while the oleophilic characteristics of the fiber permit oiland grime to be readily embedded therein, the hydrophobic properties ofthe fiber prevent water from entering the fiber to remove contaminantstherefrom.

Attempts have been made to reduce the oleophilic characteristics ofthese synthetic fibers by coating the fibers with a coating that isoleophobic, i.e., will hinder the attachment of soil or oily materialsto the fibers. Many polymer systems have been proposed which are capableof forming a film around the fibers that constitute the textilematerial, particularly acid emulsion polymers prepared from organicacids having reactive points of unsaturation. These treating polymersare known as soil-release agents.

The term soil-release in accordance with the present invention refers tothe ability of the fabric to be washed or otherwise treated to removesoil and/or oily materials that have come into contact with the fabric.The present invention does not wholly prevent the attachment of soil oroily materials to' the fabric, but hinders such attachment and rendersthe heretofore uncleanable fabric now susceptible to a successfulcleaning operation. While the theory of operation is still somewhat of amystery, soiled, treated fabric when immersed in detergent-containingwash water experiences an agglomeration of oil at the surface. Thiswater is basic in nature, and it has been determined that soilrelease isbest realized in wash water that is basic in nature. These globules ofoil are then removed from the fabric and rise to the surface of the washwater. This phenomenon takes place in the home washer during continueagitation, but the same effect has been observed even under staticconditions. In other words, a strip of polyester/cotton fabric treatedaccording to the process of the present invention and soiled with crudeoil, when simply immersed in a detergent solution will lose the oil evenwithout agitation.

Concentrated solutions of soil-release polymers have been padded ontofabrics by textile manufacturers to impart a permanent soil-releasefinish to the fabric. As the amount of soil-release polymer on thefabric is increased, the ability to release soil is increased. However,fabrics with this permanent soil-release finish possess manydisadvantages. As the amount of soil-release polymer on the fabric isincreased, the fabric has a tendency to become stiffer and lose thedesirable hand characteristic of the fabric. Thus, the upper limit onthe amount of soil-release polymer is determined by economics and theresulting adverse effect on the fabric. Fabrics with a relatively heavyapplication of soilrelease polymer'do not have the same desirableappearance and hand asthe same fabrics without the soilrelease polymer.Furthermore, practically speaking, there is a set range of soil-releaseagent that can be applied, dictated by commercial success.

Soil-release polymers are effective fabric treating agents even at verylow levels on the fabric, at which levels the appearance and hand of thefabric are not adversely affected. Thus, an ideal method of treating asynthetic fiber-containing fabric would be to reapply a very smallamount of soil-release polymer each time the fabric is washed, such asin the rinse cycle of the home laundry procedure.

Certain polycarboxylate polymers are very effective soil-release agentsat low levels on the fabric. However, these polymers cannot be appliedto fabrics from dilute aqueous solutions because the polymers are sosoluble in water that they will not deposit onto the fabric from dilutesolution.

SUMMARY OF THE INVENTION It has now been discovered that a veryeffective nonpermanent soil-release finish can be applied to fabricsusing a dilute aqueous solution of about 0.005 to 1.0 percent preferably.01 to 0.05 percent polycarboxylate polymer in the presence of awater-soluble amine. The amine serves to decrease the solubility of thepolymer sufficiently to cause the polymer to be deposited onto thefabric from dilute aqueous solution. A preferred range of amineconcentration is from 0.05 to 1.5 percent in aqueous.

Polycarboxylate polymers found to be effective soilrelease agents whenapplied from dilute solution in the presence of a water-soluble amineare those polycarboxylate polymers having an acid equivalent weight(i.e., gram per mole of carboxylate) in the range of from about 110 to175. The preferred acid equivalent weight for these polymers for use inthis invention is about 125.

The most effective polymers for use as soil-release agents applied fromdilute solutions in the presence of water-soluble amines are copolymersof methacrylic acid with ethylacrylate wherein the methacrylic acidcomprises about of the copolymer and the ethylacrylate comprises about/a of the copolymer. The methacrylic acid/ethylacrylate copolymers thatare effective have molecular weights ranging from about two thousand toabout five million, although copolymers having a molecular weight ofabout one million are preferred. The copolymers form a hydrophilic filmon the treated fibers upon drying, and afford soil releasability at thatpoint. Each subsequent treatment with the polymer serves to enhance thesoil-release characteristics of the substrate.

Water-soluble diamines have been found to be particularly effective inthe compositions of this invention; specific examples of these diaminesinclude tetramethylene diamine and N,N-dimethyl,N,N-diethanolethylene-diamine. Water-soluble monoamines which areeffective in the compositions of the present invention includeNamethylethanolamine and N-phenyl diisopropylamine. Water-solubletetramines which can be used in compositions of the present inventioninclude N,N- bis (3-aminopropyl)-l, 3-propane diamine and tris (2-aminoethyl) amine.

The proportion of water-soluble amines to the polycarboxylate polymersin compositions of the present invention ranges from about 1:5 to 40:!with the preferred range being from about 1:1 to about 30:1.

The soil-release properties of pure cellulosic fiber fabrics are muchbetter than those of synthetic fiber containing fabrics, e.g., polyesterfibers, in that the synthetic polyester fibers are hydrophobic and thusprevent the ingress of water that is necessary for cleaning the fabric,and also possess an electrical charge that attracts soil particles. Thepresent invention is therefore most primarily directed to fabricscontaining a substantial portion of synthetic polyester fibers.

The present invention may be used to treat a wide variety of textilematerials made exclusively from synthetic polymer fibers, as well asblends of natural and synthetic fibers. Examples of synthetic fiberswhich may be successfully employed in the practice of the presentinvention include those made with polyamide, acrylic, and polyesterfibers. Blends of natural and syn thetic fibers which may besuccessfully treated according to the present invention include fabricscomprising 50% polyester/50% cotton, 65% polyester/35% cotton, etc.Cellulose fibers, for example, cotton, viscose, regenerated cellulose,etc., also may be combined with the synthetic fibers.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Treating compositions were madeup of a copolymer of methacrylic acid/% ethylacrylate of a molecularweight of about one million, with the percentage of a water-solubleamine as shown in Table I.

0.24% tetramethylethylene diamine 'l.l/1 tetramethylethylene diamine0.4% N-methyl ethanolamine 0.05% tris (Z-aminoethyl) amine The treatingcompositions were dissolved in water to make solutions 0.05 percent incopolymers and the amine concentration listed. Identicalpolyester/cotton swatches were soaked in 250 mls. of the treatingsolutions for 10 minutes. The pH of the treating solutions was between 6and 7.

The treated swatches were soiled by applying to each swatch three dropsof a 1:1 mixture of dirty motor oil/- mineral oil. The oil was allowedto spread and set for three hours. The swatches were then washed in 650mls. of a solution containing one gram of a 10-2-2(anionic-nonionic-soap) commercially available laundry detergent, at 90Ffor 10 minutes, rinsed for 5 minutes, and dried.

It can be seen from the foregoing examples that this copolymer ofmethacrylic acid/ethylacrylate is effective as a soil-release agent whendeposited from dilute solution in the presence of a water-soluble amine.The composition of the invention is particularly well adapted to be usedin the rinse cycle of a home laundry system, as the copolymer in thepresence of the watersoluble amine will deposit the soil-release finishonto fabrics from dilute solution. The composition can be added directlyto the rinse water without adjusting the pH or the temperature of thewater.

None of the swatches treated in the foregoing example had chunks ofpolymer visible on the surface of the swatches, and the original hand ofthe fabrics was not adversely affected by the treatment with thesoilrelease polymer of the invention. The treated swatches appeared tohave more body than before treatment.

In addition, a slight amount of foam was generated during the treatmentprocess only by the solution containing tris (2-aminoethyl) amine; theremaining solutions were clear.

An added feature of the present invention is the prevention of soilredeposition from the wash water by virtue of the soil-release coatingson the synthetic fibers. One of the greatest disadvantages inherent inthe synthetic polymers is the feature that even after removing the soilby washing, there is the continued danger that the soil will beredeposited onto the fibers from the wash water-before the garment isremoved therefrom.

What is claimed is:

1. A composition for imparting non-permanent soilrelease characteristicsto textile fabrics comprising a copolymer of methacrylic acid and V3ethyl acrylate having an acid equivalent weight of from about 1 to 175and a molecular weight of about 2000 to about 5,000,000 and awater-soluble amine selected from the group consisting of tetramethylenediamine; N- methylethanolamine; N,N dimethyl,N'N'-diethanolethylene-diamine; N,N bis( 3-aminopropyl )-l ,3- propanediamine; tris (2-aminoethyl) amine; and N- phenyl diisopropylamine, saidcopolymer and said water soluble amine being present in a ratio rangingfrom about 1:5 to 40:1.

2. The composition of claim 1 wherein the copolymer has an acidequivalent weight of 125.

3. The composition of claim 1 wherein the copolymer consists of aboutmethacrylic acid and about a ethylacrylate.

4. The composition of claim 1 wherein the ratio of amine to polymer isfrom 1:1 to 30:1.

5. The composition of claim 1 wherein the amine is tetramethylenediamine.

6. The composition of claim 1 wherein the amine is tris (2-aminoethyl)amine.

7. The composition of claim 1 wherein the amine is N,N-dimethyl,N,N'-diethanolethylene-diamine.

8. The composition of claim 1 wherein the molecular weight of thecopolymer is about one million.

2. The composition of claim 1 wherein the copolymer has an acidequivalent weight of
 125. 3. The composition of claim 1 wherein thecopolymer consists of about 2/3 methacrylic acid and about 1/3ethylacrylate.
 4. The composition of claim 1 wherein the ratio of amineto polymer is from 1:1 to 30:1.
 5. The composition of claim 1 whereinthe amine is tetramethylene diamine.
 6. The composition of claim 1wherein the amine is tris (2-aminoethyl) amine.
 7. The Composition ofclaim 1 wherein the amine is N,N-dimethyl,N'',N''-diethanolethylene-diamine.
 8. The composition of claim 1 whereinthe molecular weight of the copolymer is about one million.